[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] TSQ accounting skb->truesize degrades throughput for large packets
On Fri, 2013-09-06 at 10:00 -0700, Eric Dumazet wrote: > On Fri, 2013-09-06 at 17:36 +0100, Zoltan Kiss wrote: > > > So I guess it would be good to revisit the default value of this > > setting. > > If ixgbe requires 3 TSO packets in TX ring to get line rate, you also > can tweak dev->gso_max_size from 65535 to 64000. Another idea would be to no longer use tcp_limit_output_bytes but max(sk_pacing_rate / 1000, 2*MSS) This means that number of packets in FQ would be limited to the equivalent of 1ms, so TCP could have faster response to packet losses : Retransmitted packets would not have to wait for prior packets being drained from FQ For a 8Gbps flow, 1Gbyte/s, sk_pacing_rate would be 2Gbyte, this would translate to ~2 Mbytes in Qdisc/TX ring. sk_pacing_rate was introduced in linux-3.12, but could be backported easily. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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